mindmap root((摆动)) swing implies a movement through an arc of something attached at one end or one side: the door suddenly ~ open. sway implies a slow swinging or teetering movement: the bridge ~ed a little and then fell. （teeter摇晃蹒跚不稳: unsteady, seesawing movement,如an inebriated man teetering as he stands一个醉酒的人站得摇摇晃晃） oscillate stresses a usually rapid alternation between extremes of direction: a fan that ~s will cool more effectively. vibrate suggests the rapid oscillation of an elastic body under stress or impact: the ~ing strings of the piano. （elastic能伸缩，如slacks that come with an elastic waistband长裤有可伸缩腰带） fluctuate suggests a constant irregular changing of level, intensity, or value: monetary exchange rates ~ constantly. waver stresses an irregular motion suggestive of reeling or tottering: his whole body ~ed as he crossed the finish line. （reel来回旋转失去平衡: to turn round and round or be thrown off balance,如a boxer reeling from the blow拳击手被打得晕头转向，即被打懵） （totter蹒跚摇摇晃晃,如he tottered before he fell他走得摇摇晃晃，然后摔倒了） undulate suggests a gentle wavelike motion: an ~ing sea of grass.